An Accreting White Dwarf Near the Chandrasekhar Limit in the Andromeda Galaxy

Tang, Sumin; Bildsten, Lars; Wolf, Walter J.; Li, K. L.; Kong, Albert; Cao, Y.; Cenko, S. B.; De, A.; Kasliwal, M. M.; Kulkarni, S. R.; Laher, Russ R.; Masci, Frank J.; Nugent, P.; Perley, D.; Prince, Thomas A.; Surace, J.

doi:10.1088/0004-637x/786/1/61

Cited by 64 publications

(99 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this is probably not true for the recurrent nova systems, in which WDs with masses close to the Chandrasekhar limit accrete H with rates close toṀ stable . This makes them good candidates for the SD channel of SN Ia progenitors (Wolf et al 2013;Tang et al 2014).…”

Section: Mass Accretionmentioning

confidence: 99%

Hybrid C–O–Ne white dwarfs as progenitors of Type Ia supernovae: dependence on Urca process and mixing assumptions

Denissenkov

Truran

Herwig

et al. 2015

Monthly Notices of the Royal Astronomical Society

107

View full text Add to dashboard Cite

When carbon is ignited off-centre in a CO core of a super-AGB star, its burning in a convective shell tends to propagate to the centre. Whether the C flame will actually be able to reach the centre depends on the efficiency of extra mixing beneath the C convective shell. Whereas thermohaline mixing is too inefficient to interfere with the C-flame propagation, convective boundary mixing can prevent the C burning from reaching the centre. As a result, a C-O-Ne white dwarf (WD) is formed, after the star has lost its envelope. Such a "hybrid" WD has a small CO core surrounded by a thick ONe zone. In our 1D stellar evolution computations, the hybrid WD is allowed to accrete C-rich material, as if it were in a close binary system and accreted Hrich material from its companion with a sufficiently high rate at which the accreted H would be processed into He under stationary conditions, assuming that He could then be transformed into C. When the mass of the accreting WD approaches the Chandrasekhar limit, we find a series of convective Urca shell flashes associated with high abundances of 23 Na and 25 Mg. They are followed by off-centre C ignition leading to convection that occupies almost the entire star. To model the Urca processes, we use the most recent well-resolved data for their reaction and neutrino-energy loss rates. Because of the emphasized uncertainty of the convective Urca process in our hybrid WD models of SN Ia progenitors, we consider a number of their potentially possible alternative instances for different mixing assumptions, all of which reach a phase of explosive C ignition, either off or in the centre. Our hybrid SN Ia progenitor models have much lower C to O abundance ratios at the moment of the explosive C ignition than their pure CO counterparts, which may explain the observed diversity of the SNe Ia.

show abstract

Section: Mass Accretionmentioning

confidence: 99%

Hybrid C–O–Ne white dwarfs as progenitors of Type Ia supernovae: dependence on Urca process and mixing assumptions

Denissenkov

Truran

Herwig

et al. 2015

Monthly Notices of the Royal Astronomical Society

107

View full text Add to dashboard Cite

show abstract

“…We carried out a coordinated, very high-cadence observing campaign with the Swift satellite (Gehrels et al 2004) to detect the X-ray flash during the 2015 outburst of the recurrent nova M31N 2008-12a (Darnley et al 2014(Darnley et al , 2015Henze et al 2014aHenze et al , 2015aTang et al 2014). This is the ideal object to detect X-ray flashes because its recurrence period is as short as a year, possibly even half a year (Henze et al 2015b).…”

Section: Introductionmentioning

confidence: 99%

X-RAY FLASHES IN RECURRENT NOVAE: M31N 2008-12a AND THE IMPLICATIONS OF THE SWIFT NONDETECTION

Kato

Saio

Henze

et al. 2016

ApJ

View full text Add to dashboard Cite

Models of nova outbursts suggest that an X-ray flash should occur just after hydrogen ignition. However, this X-ray flash has never been observationally confirmed. We present four theoretical light curves of the X-ray flash for two very massive white dwarfs (WDs) of 1.380 and 1.385 M ⊙ and for two recurrence periods of 0.5 and 1 years. The duration of the X-ray flash is shorter for a more massive WD and for a longer recurrence period. The shortest duration of 14 hours (0.6 days) among the four cases is obtained for the 1.385 M ⊙ WD with one year recurrence period. In general, a nova explosion is relatively weak for a very short recurrence period, which results in a rather slow evolution toward the optical peak. This slow timescale and the predictability of very short recurrence period novae give us a chance to observe X-ray flashes of recurrent novae. In this context, we report the first attempt, using the Swift observatory, to detect an X-ray flash of the recurrent nova M31N 2008-12a (0.5 or 1 year recurrence period), which resulted in the non-detection of X-ray emission during the period of 8 days before the optical detection. We discuss the impact of these observations on nova outburst theory. The X-ray flash is one of the last frontiers of nova studies and its detection is essentially important to understand the pre-optical-maximum phase. We encourage further observations.

show abstract

“…From results of other surveys, we know that some number of such fast novae do exist, an example being the famous M 31N 2008-12a (Shafter et al 2012;Darnley et al 2014;Henze et al 2014;Tang et al 2014; see also the MPE optical nova catalog from footnote 3), but their true frequencies in the bulge and the disk of the galaxy remain to be determined.…”

Section: Fast Novaementioning

confidence: 99%

“…We used the light curves from the PTF (Cao et al 2012) and WeCAPP (Lee et al 2012) nova catalogs with morphological classification available, the light curves from Shafter et al (2011) that have been observed in the V-band, the highquality light curves from Capaccioli et al (1989), and the sample of extragalactic novae discovered by P60-FasTING (Kasliwal et al 2011). To this compilation, we added the recently discovered very fast recurrent nova M 31N 2008-12a in M 31 with the shortest known recurrence period of ∼1 yr (Shafter et al 2012;Darnley et al 2014;Henze et al 2014;Tang et al 2014). The PTF and WeCAPP light curves were converted from R-band to V-band using the color (V −R) • = 0.16 (Shafter et al 2009) after accounting for the foreground extinction of A R = 0.15 (Shafter et al 2009) estimated using a reddening of E(B − V) = 0.062 along the line of sight to M 31 from Schlegel et al (1998).…”

Section: Appendix B: Peak Magnitudes Of Novaementioning

confidence: 99%

Constraining the role of novae as progenitors of type Ia supernovae

Soraisam

Gilfanov

2015

A&A

View full text Add to dashboard Cite

Context. With the progenitors of type Ia supernovae (SNe Ia) still eluding direct detections, various types of accreting white dwarfs (WDs) have been proposed as prospective candidates. One of the possibilities are WDs undergoing unstable nuclear burning on their surfaces. Although observations and theoretical modeling of classical novae generally suggest that more material is ejected during the explosion than is accreted, there is growing evidence that in certain accretion regimes of novae, appreciable mass accumulation by the WD in the course of unstable nuclear burning may be possible. Aims. We propose that statistics of novae in nearby galaxies may be a powerful tool to determine the role these systems play in producing SNe Ia. Methods. We used multicycle nova evolutionary models to compute the number and temporal distribution of novae that would be produced by a typical SN Ia progenitor before it reached the Chandrasekhar mass limit (M ch ) and exploded, assuming that it experienced unstable nuclear burning during its entire accretion history. We then used the observed nova rate in M 31 to constrain the maximal contribution of the nova channel to the SN Ia rate in this galaxy. Results. The M 31 nova rate measured by the POINT-AGAPE survey is ≈65 yr −1 . Assuming that all these novae will reach M ch , we estimate the maximal SN Ia rate novae may produce, which is < ∼ 0.1-0.5 × 10 −3 yr −1 . This constrains the overall contribution of the nova channel to the SN Ia rate at < ∼ 2-7%. However, if all POINT-AGAPE novae do eventually reach M ch , a significant population of fast novae (t 2 < ∼ 10 days) originating from the most massive WDs is expected, with a rate of ∼200−300 yr −1 , which is significantly higher than currently observed. We point out that statistics of such fast novae can provide powerful diagnostics of the contribution of the nova channel to the final stage of mass accumulation by the single-degenerate (SD) SN Ia progenitors. To explore the prospects of their use, we investigated the efficiency of detecting fast novae as a function of the limiting magnitude and temporal sampling of a nova survey of M 31 by a PTF class telescope. We find that a survey with the limiting magnitude of m R ≈ 22 observing at least every second night will catch ≈90% of fast novae expected in the SD scenario. Such surveys should be detecting fast novae in M 31 at a rate on the order of > ∼ 10 3 × f per year, where f is the fraction of SNe Ia that accreted in the unstable nuclear burning regime while accumulating the final ΔM ≈ 0.1 M before the supernova explosion.

show abstract

An Accreting White Dwarf Near the Chandrasekhar Limit in the Andromeda Galaxy

Cited by 64 publications

References 53 publications

Hybrid C–O–Ne white dwarfs as progenitors of Type Ia supernovae: dependence on Urca process and mixing assumptions

Hybrid C–O–Ne white dwarfs as progenitors of Type Ia supernovae: dependence on Urca process and mixing assumptions

X-RAY FLASHES IN RECURRENT NOVAE: M31N 2008-12a AND THE IMPLICATIONS OF THE SWIFT NONDETECTION

Constraining the role of novae as progenitors of type Ia supernovae

Contact Info

Product

Resources

About